Thyroid function in rats and rabbits was measured following inhalation exposure to carbon disulfide. Serum T4 activity decreased in rabbits but not in rats. Other indexes of thyroid function remained unchanged. Rabbits were exposed or treated with all combinations of carbon disulfide, cholesterol-enriched diet, thiourea, and levothyroxine. Histopathological examination did not support the hypothesis that in the rabbit carbon disulfide accelerated the atherosclerotic process through depression of thyroid activity. Other studies in rats demonstrated that exposure to carbon disulfide reversibly alters hepatic cholesterol metabolism through a mechanism that is dependent on the prior metabolism of carbon disulfide. Exposure of strain A mice for 6 months to vinyl chloride, ethylene dibromide or ethylene oxide, but not carbon disulfide or NO2+morpholine cause concentration-related increases in numbers of pulmonary adenomas that were formed. This inexpensive model may be useful in helping to identify inhalant carcinogens.